In internal combustion engines, the bearing assemblies typically each comprise a pair of half-bearings retaining a crankshaft that is rotatable about an axis. For crankshaft journal bearing assemblies, at least one half-bearing is a flange half-bearing that comprises a hollow generally semi-cylindrical bearing shell provided with a generally semi-annular thrust washer extending outwardly (radially) at each axial end. In some flange half-bearings, a single-piece construction of the bearing shell and thrust washers is used, whilst in other half-bearings, the bearing shell and the thrust washer are loosely mechanically engaged with clip-like features, and in a further type of half-bearing the thrust washers are permanently assembled onto the bearing shell by deformation of engagement features.
Known clip-like features for loosely mechanically engaging a thrust washer around the outer surface of a semi-cylindrical bearing shell, at an axial end, have a generally semi-annular panel with a pair of hooking lugs (tabs) projecting inwardly from the semi-circular inner edge. The hooking lugs hook into corresponding openings in the bearing shell, in use, when the thrust washer is connected around the outer surface at an axial end of the bearing shell. The inwardly projecting hooking lugs are located to either side of the crown of the bearing, towards the joint faces, and are shaped to enable the thrust washer to be assembled onto the bearing shell when the bearing shell has been resiliently deformed by pinching together the joint faces (circumferential end faces). The arrangement by which the hooking lugs engage with the openings (recesses) prevents separation once the bearing shell has returned to the relaxed position, and also prevents separation when the bearing shell has been slightly pinched together through being held in an interference fit with a housing, within the full bearing assembly. The hooking lugs have a uniform thickness and are machined to be thinner than the main semi-annular panel of the thrust washer, to enable the use of (axially) narrow openings in the bearing shell. One or more stabilisation lugs may be provided intermediate the hooking lugs, projecting inwardly from the inner edge of the semiannular main panel, to reinforce the connection between the thrust washer and bearing shell, to prevent wear leading to substantial relative rotation of the thrust washer and bearing shell.
U.S. Pat. No. 4,533,261, EP2233759 and WO2013068106 illustrate flange half-bearings, in which thrust washers are loosely mechanically engaged with bearing shells with clip-like features by the engagement of thin hooking lugs of uniform thickness within openings in a corresponding bearing shell.